The importance of fine particulate organic matter (FPOM) as an energy source in streams in well documented and considerable data exist on FPOM transport and benthic storage. An important aspect necessary to complete understanding of the dynamics of this material is information on FPOM transport distance, rates of FPOM deposition and resuspension, retention time on the stream bed, and capture by aquatic insects. This project will use a recently developed method to label FPOM particles with 14C. The labeled particles will be used to study the dynamics of FPOM transport under natural stream conditions. The processes which will be studied include movement of FPOM, rates of loss from the water column (sedimentation, deposition), and lengths of times the articles remain in place (retention and resuspension). The pattern and magnitude of accumulation of transported 14C-labelled FPOM by aquatic insects will also be evaluated and provide data that would permit testing of several critical assumptions inherent in current methods of constructing carbon budgets and applying the Nutrient Spiraling Concept to lotic ecosystems. The investigators are well qualified to perform this type of research and the facilities at Idaho State University are more than adequate.
